Saw blade alignment tool

ABSTRACT

A device of utility in precisely setting the angular relationship of a circular saw blade of a radial bench type power saw, which includes a special protractor defined by removing adjoining segments of the linear leg and the curved leg thereof, and a modified T-square including a head piece having a curvature matching that of the curved leg of the protractor and a connected ruler blade extending radially toward the center of said protractor.

The present invention relates generally to the machine shop art. Moreparticularly the present invention relates to a novel tool device ofutility in the wood working art, and, most particularly, to the woodworking art as pertains to the what may be termed expensive woods suchas teak, cherry, and others known in the art.

In the fabrication and sawing of woods, it is usually necessary toemploy a radial, bench type power saw in cutting the planer pieces ofwood at a particular and specific angle in accordance with that desiredas perhaps illustrated in a blue print or shop print of the part beingfabricated.

The more precisely accurate the angle, the better will the cut piece fitinto the structure of which it is a part such as price of furniture,cabinetry or the like.

Now commercial bench type, radial, power saws frequently embody orincorporate an angle setting guide integral with the machine. Thisusually takes the form of a built-in circular guide element with degreemarkings and provisions for loosening the power saw device via setscrews, wing nut type devices or the like, then adjusting the saw sothat an index lines up with the proper degree marking on the circularmember. These have been found to be extremely inaccurate, eg., rarelyaccurate to within 3 degrees. Inaccuracies in sawing the angle desiredfor a particular object piece of wood, of course, yields waste since thewood piece cut at a wrong angle will not match in forming the desiredassembly of pieces.

To reduce, eliminate or avoid the waste, a system of trial and error hasbecome common practice in the shop. First, an initial cut is made bylocating the practice piece of wood against the table fence of thecommercial power saw apparatus and then proceeding with an angle cutwhich is measured and usually found to be inaccurate. Then the bladeangle is adjusted to a second trial angle. Another cut is then made on asecond piece of wood at the second rial angle. Measurement usuallyreveals error and the necessity of a third adjustment of the blade toyield precisely the desired angle. This "trial and error" method isusually necessary to arrive at the angle desired, before commencing the,saw cut on the piece of expensive wood with some assurance or confidencethat the angle of cut will be that desired, as indicated on the printbeing followed on the particular job. Repetitive commercial productioncan then proceed, recognizing that after a time it is usually necessaryto recheck the angle setting.

Clearly and obviously the trial and error method consumes a considerableamount of time and yields a considerable amount of waste. Both of thesetranslate into higher cost of the finished item which could be reduced,and can be reduced, by the use of the tool device of the presentinvention, which allows the radial bench type power saw to be accuratelyand quickly adjusted to the precise print angle or the precise angledesired with confidence so that the cut will be accurate andaccomplished in a minimum amount of time and with no waste therebyreducing both time and materials necessary for a particular job or jobs.

Over the years, a number of tools, gauges, guides, and such devices andapparatus have been developed and are described in the patent art. Thefollowing patents disclose such devices; U.S. Pat. Nos. 1,601,645;2,595,322, 4,315,373; 4,608,761; 4,779,354; 4,843,728; 5,121,553;5,121,544. The devices shown in the foregoing patents, however, while ofinteresting historical significance do not serve the purpose of the tooldevice of the present invention. The devices illustrated in theforegoing patents are exceptionally complicated, and additionally, failto perform satisfactorily. Others of the device, as shown, are actuallydirected to different purposes and are structurally complicated;composed of too many parts and even then fail to accomplish theaccuracy/precision and speed possible with utilization of the tool ofthe present invention.

It is a principal object to the present invention to provide animproved, yet simplified tool device of utility in adjusting/setting thecircular saw blade of a radial, bench type, power saw at a precisecutting angle as desired or per print.

It is another object of the present invention to provide such acombination protractor, T-square tool device which features an elongatebase leg of precise dimension, to wit 145/16 inch, thus yielding aprecise gauge on the outer perimeter of the curved leg in which quarterinch markings from 0 to 90 degrees, each correspond to a single degreeof arc and thus most convenient for the person using the device to setthe angle desired by measuring in inches that corresponding to thedegrees according to the scale, 1 inch equal 4 degrees.

It is a further feature of the present invention that the device is sodesigned that it can be used on one face, or the other, depending uponthe particular angle as measured from the base leg as desired for thesaw blade in accordance with the shop print or the like.

Still another object of the present invention is to provide such a tooldevice consisting of the truncated protractor member and modifiedT-square which is adapted for setting not only the desired horizontalangle of the saw blade but the departure of the saw blade from verticalas desired for bias cuts.

It is a further object of the present invention to provide a device, asdescribed, which is extremely useful, convenient, simple, and speedilymanipulated as to translate the desired shop print angle to the workpiece thereby avoiding trial cuts and other errors and/or the need fortrial cuts.

The foregoing objects and, as well, other objects of the presentinvention will become apparent to those skilled in the art from thefollowing detailed description, taking in conjunction with the annexedsheets of drawings inclusive of seven Figures, in which there isillustrated the precise embodiment of the present invention in terms ofits component parts, and, as well, illustrating the use of the device ona various types of power saw and the integral cooperating table usuallyassociated therewith.

IN THE DRAWINGS

FIG. 1 is a top plan view of the tool device of the present inventionconsisting of a truncated protractor and a modified T-square.

FIG. 2 is likewise a top plan view of the tool device of the presentinvention, but with the truncated protractor shown inverted for apurpose to be explained.

FIG. 3 is an edge view taken on the line 3--3 in FIG. 2.

FIG. 4 is an edge view like FIG. 3, but taken on the line 4--4 in FIG.2.

FIG. 5 is a three-quarter perspective view of the device shown inoperative relationship with a radial power saw.

FIG. 6 is a view similar to FIG. 5, but showing an alternative/variantuse of the present invention to illustrate the scope of usages.

FIG. 7 is a side elevation view, showing in a variant usage, the settingthe saw angle as a departure from vertical eg. for bias cuts etc.

In its simplist embodiment the present invention comprises, incombination, a truncated protractor in which half of the base leg andless than half of the adjoining angular segment has been broken away,said protractor including angular markings and a cooperating modifiedT-square having a head piece adapted to movably engage the outerperimeter of the remaining arc portion of the protractor, while theelongate, central ruler portion extends radially and has a bias cut endadapted for registration with the bias cut end of the base leg.

Referring now more specifically to the drawings, there is disclosed, inFIG. 1, the tool device of the invention comprising the truncatedprotractor 11, and the modified T-square 30 in mutually operativerelationship. The base leg 12 of the protractor is bias cut on the line13 as to intersect the center of the base leg (before cutting); whilethe circular leg 15 is radially cut at 16 as shown and leavning a space20 between the cut ends. In accordance with the invention the circularleg 15 bears degree markings 17 on the upper surface and inch divisionson the outer perimetric edge 15b thereof. As particularly shown in FIG.3, the inch markings are subdivided into one 1/4 inch divisions for apurpose to be explained. In accordance with a preferred embodiment ofthe present invention, the lower edge 12a of the remaining base leg 12measures 145/16 inches in length; while the width of the base leg 12,measured from the lower edge 12a to the upper edge 12b, measures 31/16inches. Similarly the width of circular leg 15 measured from the innerperiphery 15a to the outer periphery 15b is likewise 31/16 inches. Inaccordance with one embodiment of the invention, the inner periphery 15aof the circular leg segment (see FIG. 4) bears a scale measured inmillimeters. The thickness of the truncated protractor, as shown inFIGS. 3 and 4, preferably measures about 3/8 inch. The circular leg 15is radially cut, as indicated, at 16 which would represent a total of,about 110-120 degrees measured from the origin 15c of the circular leg,or 30 degrees from the 90 degree mark situated directly above theextremity 14 of the base leg 12.

In accordance with the present invention the space 20, located betweenand created by the bias cut 13 and radial cut 16, serves as aconvenience feature in the use of the tool device of the presentinvention, in a manner as will be explained hereinafter.

The modified T-square 30 is composed of a head piece, 31 and a linear,ruler like blade, 32 extending, as shown, vertically down to terminatein a bias cut, 33 yielding a pointed extremity, 34 adapted, as shown,for coincident registration with the pointed extremity 14 of the baseleg 12 of the protractor component 11. The T-square head piece 31includes the curved edge 35 which matches exactly the curvature of theouter perimeter 15b of curved leg 15 whereby it may move slidingly ineither of the directions indicated by the arrows 37 much in the mannerof a conventional T-square. The correct and desired angular relationshipof the edge 36 of blade 32 is achieved by insuring firm contact of theedge 35 in the manner indicated and coincident registration of theterminus 14 of the leg 12 and the terminus 34 of the blade of rulercomponent 32. With this arrangement the blade will intersect thecircular leg in any one of a variety of angular relationships via degreemarkings 17. It will be appreciated that rather than using the degreescale 17 of the outer circular surface, one may optionally read eitherthe 1/4 inch division markings on the outer perimeter 15b of thecircular leg 15, or the metric division scale on the inner perimeter 15aof the circular leg 15.

Referring now to FIG. 2 the truncated protractor 11 (via cuts 13 and 16)is shown lying in horizontal flat relationship but flipped over from theposition as shown in FIG. 1. This reverse position reveals surface whichalso contains degree marking ranging from zero as shown to approximately115-125 degrees and again defining a space 20. In accordance with theinvention the use of the device in this flipped or reverse positionrequires a second modified T-square member 40 which is essentiallyidentical to the modified T-square 30 of FIG. 1, excepting that the biascut 43 is opposite to the bias cut 33 of modified T-square 30, wherebythe terminal end 44 is adapted for registration with the terminal end 14of base leg 12, whereby sliding contact of the head piece 41 as shown,coupled with coincidence of the terminal end 44 of the ruler portion 42with the end 14 of leg 12 permits the ruler portion to be positioned inany desired angular relationship with respect to the bottom edge of 12aof base leg 12. In all other respects the arrangement as shown in FIG. 2is identical to that shown in FIG. 1.

It is a feature of the present invention that the dimension of the lowerleg and of the width of the lower leg and of the circular leg areselected in order to achieve a particular use advantage. Thus the lengthof the lower leg is 135/16 inches while the width of the base leg andcircular leg are each 31/16 inch. The application of geometricprincipals to the circular protractor so constructed yields theresultant that 1/4 of length on the perimeter 15b corresponds to 1degree of angular relationship between the edge 36 of the modifiedT-square and the base edge 12a of the lower leg. This enables one todetermine or to set the modified T-square of any desired angularrelationship using the inch scale on the perimeter rather than thedegree scale 17 on the upper surface. The geometry thus provides that adistance of 1 inch on the peripheral corresponds at 4 degrees; andsimilarly 2 inches equals 8 degrees. Similarly 15 inches corresponds to60 degrees while 221/2 inches corresponds to 90 degrees where the zerodegrees begins at the origin 15c and continues on the perimeter to the221/2 inches mark at the T-square position as shown in either FIG. 1 orFIG. 2.

In a similar fashion, the metric scale on the inner periphery 15a of thecircular leg 15 permits the use of the metric scale in setting theangular relationship of the edge 36 of the ruler component 32 ofmodified T-square 30 with respect to the base leg 12. As indicatedearlier, this is made possible by the precise formation of the lowerbase leg to be 145/16 inches in length and the width of the protractorangular and base legs at 31/16 inches. The geometry of the choice ofthese values creates a relationship of 5 millimeters of distance on theinner perimeter corresponding to one degree of arc. Similarly 50millimeters corresponds to 10 degrees of arc; 100 millimeterscorresponds to 20 degrees of arc and 200 millimeters equal 40 degrees ofarc, etc.

Referring now more specifically to FIG. 5, the combination tool deviceof the present invention consisting of the truncated protractor member11 and modified T-square member 40 (See FIG. 2) is shown resting flushlyon the horizontal surface of table T of a radial power saw apparatus 50shown in dotted/phantom line, as such forms no part of the presentinvention. The radial power saw apparatus 50 includes a horizontalsupport boom 51 from which depends appropriately moveable transmissionand gear housing 52 and safety shield 53 partially enclosing the upperhalf of saw blade 54 in vertical angular relationships positionedflushly against the outer edge 46 of ruler blade 42. The radial powersaw table T also bears an elongate linear fence 56, including edge 56aagainst which the base leg 12a of protractor 11 abuts and movesslideably, as desired, with the fence serving as a base reference insetting the angular relationship of the saw blade 54 for the particularjob. Thus the radial power saw housing 52 includes an appropriateadjustable nut which when loosened allows the blade to pivot to anydesired angular relationship with respect to the fence 56. If thespecification or print calls for cutting piece's of expensive teak woodat an angle of 30 degrees from the normal/perpendicular position of theruler blade 42 as shown in the drawing which defines an angle of 90degrees with respect to the fence; one simply slides the head piecealong the periphery 15b of the circular leg 15 at a distance of 30degrees as read on the degree scale 17 on the upper surface.Alternatively, one may slide the head piece a distance of 7.5 inches asmeasured on the outer periphery 15b intersected by the edge 46 of theruler 42 of the modified T-square 40. (Thus 30 degrees time 1/4 equals7.5 inch) The use of the inch markings on the periphery 15b, rather thandegree markings on the fence, is frequently much more convenient for theunskilled operator.

The face of the saw blade 54 in abutment with the edge 46 defines theoperative relationship of the blade and the ruler, while the alignmentand registration of the terminal ends of the base leg 12 and the ruler42 coupled with the proper reading on the periphery assures the properdesired relationship of the saw blade; again so long as the base 12 isin firm abutment with fence 46. It then becomes a simple matter totighten the appropriate nut to fix or set the angular relationship ofthe blade, whereupon the modified T-square 40 can be removed/lifted fromthe site, while the modified protractor can be slidably moved along thetable with no interference of the saw with any part of the protractor byreason of the space between the bias cut edge 13 of the base leg 12 andthe radial cut edge 16 of the circular leg 15.

Without the space identified by the reference numeral 20 in FIG. 2, itwould be necessary to raise the entire radial power saw assembly 30 inorder to permit removal of the protractor, thus clearing the work areafor the actual sawing operation. With the device of the presentinvention conveniently and quickly removed from the work site; thepieces of expensive material to be cut can be sequentially and quicklyurged against the fence and the saw blade while operative components 52are manipulated to make the desired cut as to meet the requirements ofthe drawings, specifications etc.

A principal advantage of the device of the present invention is that itpermits a job change over to a different saw cut angle in a quick andeasy manner, in that, with the table T top surface cleared of anyresidual waste, the protractor device 11 can be moved flushly along thetable top to bring it and the saw 54 into operative relationship as inthe manner/relationship shown in FIG. 5, without requiring any verticalheight adjustment of the saw. Similarly the protractor device of thepresent invention maybe utilized in the position shown in either FIG. 2or FIG. 1 as meets the conditions called for at the job site at thattime. It is desirable that the circular leg 15 extends sufficientlybeyond the 90 degrees position so that angle adjustments may be made oneither side of the 90 degree position (See FIG. 5), without requiringthe protractor to be flipped over onto its other side, for example to aposition as shown in FIG. 1.

Referring now to FIG. 6, there is shown a somewhat similar bench ortable saw 70 featuring a slotted horizontal table top 71, a fixed fence72 and a slot 73 thru which projects, vertically upwardly, the radialsaw blade 74. Reference numeral 75 identifies an adjustment control knobor wheel for the saw assembly. Reference numeral 76 identifies anadjustable fence, via nob 77, which is moveable linearly in slot 78 orslot 79. In this embodiment, the combination tool of the present iscomposed of the truncated protractor 11 and the modified T-square 40 asshown in mutual operative relationship as in FIG. 2. In this embodiment,the novel tool device is used to adjust the angle of the moveable fence76 with respect to the angle of the saw blade 74 which is fixed. Hereagain the space 20 between the cut edges 13 and 16 of the truncatedprotractor 11 permits easy movement of the protractor 11 which would beimpossible if the protractor were not truncated in the manner asproscribed by the present invention. At the same time, the size of theprotractor and the interrelationship of the modified T-square and thetruncated protractor together with the integral scales, both in degrees,inches, and centimeters permits one to very easily set the angle of theadjustable fence 76 with respect to the saw blade in order that thedesired angle of cut on the work piece's can be achieved. Once that isset by manipulation of the modified T-square, in the manner previouslydesired, the adjustable fence is fixed by tightening the knob 77, whilethe truncated protractor and modified T-square can be quickly and easilyremoved from the site. Then the combination of the angle adjusted fence76 and the permanent fence 72, coupled with the appropriate manipulationof the pieces to be cut, allows the desired job to be completely rapidlyand accurately.

Referring now more specifically to FIG. 7, there is shown a desirablevariant use of the tool 11 and T-square 30 or 40 to adjust a saw bladeused to bias cut the edge of a work piece. Thus power table saw assembly60 is inclusive of the housing 61, a work table top 62, control oradjustment wheels 63 and the power saw blade 64 extending verticallyupwardly through a suitable opening in the table top for an appropriateoperative distance above the surface of said table top 62. In this setup, as described, the device of the present invention consisting of thetruncated protractor 11 and the ruler 30 cooperating is shown withprotractor 11 vertically upstanding on edge which is in slidingrelationship with the table top 62. At the same time the T-square 30 issituated with the head piece directly above the saw blade 64 and withthe terminus of the lower leg 12 and the terminus of the ruler 32 incoincident registration, while the edge 36 of ruler 32 is in flushabutment with the vertical surface of the saw blade 64. Now, in theposition as shown, the ruler 32 is coincident with a 90 degree readingon the upper surface 17 of the circular leg. At the same time the rulerintersects 15b to yield an inch reading of 22.5 inches. In this view thearrows 65 designate a desired change in angular relationship of thepower saw blade 64 from the vertical or 90 degree angle, shown in solidline, to an angle defined by the reference numeral 64a, in dotted line.In this application suitable loosening of the saw blade coupling wouldpermit the blade 64 to be tilted to the position identified as 64a. Nowwith the device, the precise angle desired to achieve position 64a canbe achieved by moving the head piece 31 to the right while maintainingsliding contact with the peripheral edge 15b and registration of theterminal ends of leg 12 and ruler 32 until the precise readingcorresponding to that desired by the print or specs is readable indegrees on the surface 17 or on inches on the periphery 15b. When thedesired angle is achieved the saw blade adjustment is tightened tosecure the blade at the desired angle whereupon the device T-square 30and protractor 11 can be easily removed. Clearly, the modified eg.truncated, protractor construction of the present invention permits theachievement of the precise angle in a swift and convenient manner whichis not possible with any other device. Accuracy and speed are achievedin adjusting the angle of the saw blade 64 respecting the table top 62as illustrated in order that a plurality of uncut stock pieces of woodor other material maybe sequentially manipulated through the sawingoperation to yield a precise bias edge cut without expensive trial anderror.

The foregoing detailed description taken in conjunction with thedrawings reveals both the uniqueness and the utility of the tool deviceof the present invention. As can further be seen the tool device iscomposed of a number of unique features which operate independently andcooperatively to provide a tool device of utility, and, in addition,manifest unusual capabilities with the features of novelty combined in asingle tool device of the invention.

In no particular order, the novel features are seen to include thetruncated nature of a fairly conventional flat protractor which permitsthe device to lay flat on the horizontal surface of at able saw and itseasy movability without lifting into a position essentially surroundingthe saw blade extending vertically above the surface of the table. Thecooperating modified T-square member with its head piece in slidingrelationship with the outer perimeter is adapted to have its ruler/bladein flush abutment with the upstanding vertical surface of the saw bladesuch that the specific degree markings on the protractor can be read atthe intersection of the T-square ruler with the markings on the uppersurface of the protractor. It will be recognized that the degreemarkings are present on both flat surfaces of the angular leg near theperimeter, such that the protractor can be flipped over to meet theexigent circumstances. The particularly useful feature of the presentinvention that the protractor is fabricated to a physical size such thatthe linear (elongate) leg of the truncated protractor measures 145/16inches. By reason thereof, of course, the curved leg has a perimetercorresponding to a circle having a radius of 145/16 inches. The latterdimension was selected because a circle of such radius has acircumference of very close to 90 inches. In a circle of 90 inchescircumference, each 1/4 inch corresponds to one degree eg. 90 degreesdivided by 360 degrees equals 0.25 inches; which is the same as 1/4inch. In accordance with the invention the perimeter of the modifiedprotractor of the invention bears or is inscribed with inch markingssubdivided into 1/4 inch divisions.

As indicated earlier this translates to 4 degrees per inch, etc. whichrelationship is of extreme utility for a workman operating a radialpower saw to calculate the proper setting of the blade angle in aprecise manner with respect to the straight edge of the elongate leg.The latter in turn is, of course, lying flush against a fixed oradjustable reference "fence" normally present on the table of a radialbench type power saw.

Contemplating further, constructional features desired to enhance theutility of the tool device it was envisioned that the base leg shouldcoincide in length with the radius via the bias cut (as shown in thedrawings) to designate a pointed end corresponding to the center of thecorresponding circle. This feature cooperates with the bias end cut ofthe ruler or blade portion of the modified T-square to providepreciseness with the pointed ends in registration as described earlierto assure consistency in readings in degrees or inches as may be mostsuitable to the particular craftsman.

While the protractor could have been truncated at the 90 degree mark andthus constitute one half of a protractor; it was concluded that thecircular leg should extend, most preferably, beyond 90 degrees in orderto facilitate use of the modified protractor, and particularly thelocation of the head piece in the region of the 90 degree marking,permitting readings to approach 10, 15 and even 20 degrees beyond the 90degree mark without the necessity of having to invert the protractor onits opposite surface.

In a preferred embodiment, the width of the base leg and the curved legwere set at a dimension of approximately 31/16 inch. This dimensioncoupled with the 145/16 dimension of the base leg (and radius) and thegeometry of the circle in question allows marking of the inner perimeterwith a scale of metric units according to a relationship of 5millimeters per 1 degree of arc, etc. Thus 20 degrees correspond to 100millimeters; 40 degrees corresponds to 200 millimeters and so forth.Individually, and together, the features, as above described, provide anovel tool device for use in conjunction with a radial bench type powersaw. Particularly valuable, of course, is the preciseness of measurementwhich can be achieved with consistency whereby the device is of extremeutility in the use of the table power saw in cutting expensive materialswherein loss due to waste or mistakes etc etc would otherwise result inincrease costs contrary to the savings that are possible with the deviceof the present invention.

It will be understood that the modified/truncated protractor componentof the tool device of the present invention may be fabricated of avariety of materials. Both due to ease of fabrication and toughness avariety of plastic would appear to be a logical choice, particularlysince plastic lends itself to molding. Further molding can also beemployed to impart the markings both of the angle division markings onthe surface near the perimeter, the inch markings on the edge perimeterand the millimeter markings on the inner periphery. Although not shown,it would be convenient to have the linear leg bear length dimensionsalong its lower edge.

Given the nature of modified T-square members 30 and 40 (FIG. 1 and FIG.2); it would be appropriate to fabricate these items of a plasticmaterial. Given the toughness and ease of fabrication it is alsoenvisioned that the T-square would likely be fabricated in two pieces,in the interest of economy followed by securement.

While thickness of the components of tool device of the presentinvention is not seen as critical, it would appear that practicallysuggest a viable range from 1/4 to 1/2 inch in thickness; with 3/8 inchbeing preferred as proportionately appropriate to the size of theoverall device.

From the foregoing specification and drawings; it will be appreciatedthat many obvious changes and modifications will become apparent tothose skilled in the arc and all such obvious modifications are intendedto be included within the scope of the present invention unless suchwould due violence to the scope of the appended claims.

I claim:
 1. A tool/device, for setting/adjusting the cutting angle ofthe circular saw blade of a radial, bench-type, power saw comprising, incombination;a generally flat, truncated protractor member, and at leastone cooperating T-square member, said truncated protractor membercomprising a primary elongate/base leg and, connected at one end, acurved leg, defining the arc of a circle, extending at least 90 degrees,but less than 180 degrees from said elongate/base leg, said curved leghaving upper and lower surfaces connected by a curved peripheral edge,said base leg defining/corresponding to the radius of said arc andmeasuring 145/16 inches; said T-square including a head piece having aworking edge surface congruent to and movable in slidable relationshipwith the perimeter of said curved leg.
 2. The tool device, as claimed inclaim 1, wherein said curved leg bears degree markings on the uppersurface.
 3. The tool device, as claimed in claim 2, wherein the terminalend of said base leg is bias cut to terminate in an index correspondingto the center of said arc.
 4. The tool device, as claimed in claim 3,wherein said T-square includes a linear ruler member terminating in abias cut index adapted to coincide with the index of said bias leg, assaid T-square moves in contacting relationship about the curved legperimeter.
 5. A tool device, as claimed in claim 3, wherein the curvedleg bears quarter inch markings along the peripheral edge.
 6. The tooldevice, as claimed in claim 5, wherein said curved leg measures 31/16inch in width.
 7. The tool device, as claimed in claim 6, wherein saidbase leg measures 31/16 inch in width.
 8. The tool device, as claimed inclaim 7, wherein the inner circular edge of said curved leg bearsmarkings in millimeters and in 5 millimeter spacings.
 9. A tool device,for use with a table, power saw unit having a circular saw bladeextending above said table comprising; in combinationa modifiedprotractor, having a central opening, devoid of adjoining portions ofthe straight leg and circular leg of said protractor therebyleaving/defining a space/passageway leading to said central opening anda modified T-square having a curved head piece conforming to thecurvature of the remaining curved leg of the protractor and adapted forsliding circular movement thereon, said curved leg portion containingdegree markings on its flat upper surface adjacent to the perimeter,said space/passageway accommodating sliding movement of said protractoron said table and into surrounding relationship with said circular sawblade situated in said central opening.
 10. A tool device, as claimed inclaim 9, wherein said modified T-square includes a connected,ruler/blade extending toward the center of said straight leg,corresponding to the center of the circle defining said curvature.
 11. Atool device, as claimed in claim 10, wherein said protractor having acircular curvature corresponding to a radius of substantially 145/16inches.
 12. A tool device, as claimed in claim 11, wherein said curvedleg portion includes, additionally, 1/4 inch division markings on itsouter edge periphery.
 13. A tool device, as claimed in claim 12, whereineach of said straight leg and circular leg measure 31/16 inch in width.14. A tool device, as claimed in claim 13, wherein said curved legportion includes an inner edge periphery which bears along its lengthdivisions measured in millimeters.
 15. The combination of a truncatedprotractor having an elongate linear base leg with a curved legconnected thereto, said protractor, having a central opening, created bya radial line severing a portion of the linear base leg and theconnected curved segment, thereby defining a void or passagewayconnecting to said opening and a modified T-square featuring a curvedhead piece matching the curvature of said protractor, and a connectedruler/blade extending radially toward the center of said truncatedprotractor.
 16. The combination of claim 15 wherein said protractor hasa circular edge bearing 1/4 inch divisions.
 17. The combination of claim16 wherein said protractor features a curved leg of which the curve is asegment of a circle measuring substantially 90 inches in circumference.18. A modified/truncated protractor consisting of a linear base leg andan integrally connected curved bearing degree markings, in which thetruncation leaves substantially one-half of the normally linear base legand more than one-half of the circular leg enveloping a central openregion, said truncation leaving void/clearance adapted to permit a sawblade extending above a work table surface to be surrounded by saidtruncated protractor responsive to sliding movement of said modifiedprotractor member upon said work table surface and to assume a positionof angular relationship with said base leg as determined by the degreemarkings.
 19. The device as claimed in claim 18 wherein said base legmeasures 145/16 inches in length, and, in addition, to degree markings,said curved leg bears on its outer edge periphery markings in inches,and by reason of the dimension of said base leg, each quarter inchmarking will correspond to one degree of angular relationship or oneinch will correspond to 4 degrees of angular relationship.